Maul2D v1.0.0

Maul2D 1.0.0

Deterministic across eight platform cells, rollback-native,
journal-replayable, red-teamed six times, banded against Box2D v3 in
behavior and now within one and a half times of it in active-scene
speed with portable C. The contract: cross-platform bit determinism,
bit-exact rollback, replayable history. The guide in docs/ is the
ten-minute tour.